The present invention relates to a new and improved construction of a chuck device or mandrel for a bobbin tube or sleeve of the type used for supporting thread packages of textile yarns or threads comprising a thread severing ring and a thread guide ring.
In the commonly assigned U.S. Pat. 3,801,038, granted Apr. 2, 1974, and entitled "Chuck For A Tube Or Sleeve And Serving As A Bobbin Support", there is disclosed a chuck device of a thread winding machine for endless filaments or threads with an automatic bobbin or package tube change device in which two package tubes alternatively take-up the thread delivered at a high speed and after reaching a desired package or bobbin size, with simultaneous transfer of the thread to the empty package tube or sleeve, are rocked out of a work position into a waiting position. During the thread transfer the chuck is axially displaced, and the thread which is not being traversed, is caught by the thread guide ring and severed by the thread severing ring and thereafter is wound onto the empty package or bobbin tube with a number of reserve windings. The thread caught by the thread guide ring is clamped with the aid of clamping means between the thread guide ring and the thread severing ring and is seized and cut by the teeth of the thread severing ring. In order to ensure the free removal of the starting end of the thread clamped between the thread guide ring and the thread severing ring, upon completion of the winding process and while the completed package is doffed, the thread guide ring is arranged to be axially movable.
This state-of-the art chuck device is associated with the following disadvantages. The thread or the like is not always sufficiently clamped between the thread guide ring and the thread severing ring, so that sometimes the thread is not cleanly severed. Since either the thread guide ring or the thread serving ring must be arranged to be axially movable the equipment design is complicated.